In devisingviableenergyefficiency policiesthatcanreducethegreenhousegasemissionsofexisting
dwellings (e.g.UK'sGreenDeal),dataarerequiredoncurrentinsulationlevelsanditsinfluences. One
such datasourceistheseldomusedUKEnergySavingTrust'sHomesEnergyEfficiency Database(HEED),
which thispaperinvestigatesusingNorfolkUKlocalauthoritiesasacasestudy.TheHEED'sreactiveand
longitudinal datacollectionstrategiescontributetounderlyingbiases,whichisthelikelyreasoningfor
its differenceswiththeEnglishHousingSurveyandUK2001Census.Thesedifferenceshadacascading
effect inthattheymanifestedthemselvesintheindicative financial andcarbonassessmentsundertaken.
Similarly,samplingconcernsalsoimplicatedcorrelationssurroundinginfluences ofcurrentdwelling
insulation levels.Providingoneistransparentaboutpotentialbiasesanddataconcerns,theHEEDcan
play asubstantialroleinguidingpolicydecisionsandunderstandingdwellingstockcharacteristics(e.g.
what makesdwellings ‘Hard toTreat').Inparticular,itsvast(national)geographiccoverageyethigh
resolution enableslocalcontexttobeexplored:afactorthatthisstudyshowstosignificantly shape
insulation levels.